The objective of this proposal is to evaluate the potential for delivering DNA vaccines via transcutaneous immunization technology (TCI). The potential advantages for combining DNA vaccine and TCI technologies are related to the ability of DNA vaccines to elicit the production of cytotoxic T lymphocytes and humoral responses recognizing conformational determinants. The likelihood of success for DNA vaccination via TCI is significant since preliminary data show that antigens the size of virus particles are immunogenic in this approach. We will examine the feasibility of delivering DNA vaccine vectors that are condensed into small, nuclease resistant particles, or packaged into non- enveloped virus capsid coats. Using green fluorescent protein expression as a readout, conditions will be developed to optimize transcutaneous delivery of polyethylenimine-condensed DNA into epidermal dendritic cells. The effects of various TCI adjuvants on delivery will also be examined. To optimize the induction of humoral and CTL responses via DNA TCI, a vector encoding influenza virus nucleoprotein will be employed. Finally, we will also encapsulate DNA vaccines into SV4O virus capsid coats due to the demonstrated ability of such particles to protect DNA from nuclease attach and efficiently deliver plasmids into the nucleus of mammalian cells in vivo and in vitro. PROPOSED COMMERCIAL APPLICATIONS: The development of a Transcutaneous tetanus booster could decrease the risk of immunization- related needle sticks and associated needle-borne disease, increase compliance with immunization protocols, improve access to vaccination by eliminating the need for trained personnel and sterile equipment to achieve immunization and reduce the complications related to physical skin penetration in successful immunization. Efficient delivery of DNA for vaccination could open the use of this strategy for a number of vaccines where it is presumed that DNA immunization is advantageous.